A car is a form of transportation. But so is a bicycle. When a paper is discussing where a subject (say the car) fits into such a system and contrasting the car with the bicycle what should that section of the paper be called?
In my case the paper deals with computer science and a popular way to implement a design principle. The section deals with showing that the implementation discussed is not the only implementation that fulfills the principle by briefly introducing another popular though older implementation, contrasting with it and explaining how both can fulfill the design principle.
You can do all the same things in a paper about a car, transportation, and a bicycle. Just thought they would be a little more accessible examples.
I'm hopping for a word or phrase that makes clear that the section will discuss things other than the subject but only to make clear what the subject is and is not.
If it helps, the section is a subsection to the overview that explains how it works at a high level without getting into examples.